I'd say one of the biggest problems is there's no progressive nerf to SoO like there was for ICC or DS to counteract the high turnover of raiders. Using item upgrades for that purpose is nice on paper, but the problem is that is contingent on the players present, while the zone-wide debuff sidesteps that problem.
Not to mention back in ICC's days there was still Ruby Sanctum for variety's sake. My guild stopped working on H Lich King 25 for that and it was at least entertaining (not to mention we actually beat H Halion 25, which made people happy).